Studies at our Center have indicated that subjects receiving a high salt diet had lower plasma concentrations of quinidine than they were receiving a low salt diet. We will assess systemic clearance, renal clearance and non renal clearance. P-glycoprotein mediated processes, nonrenal clearance and secretion clearance, will be modulated by dietary sodium. We were having recruitment problems and have had to adjust the protocol to make recruitment easier. It is anticipated that we will be able to continue without any problems.